Tufted Duck Aythya fuligula 鳳頭潛鴨
Category I. Abundant winter visitor.
IDENTIFICATION
Feb. 2012, Michelle and Peter Wong.
40-47 cm. Rather compact diving duck with a crest (long on breeding plumage male, shorter tuft in other plumages) and, in flight, white belly, underwings and broad wing bar across all flight feathers, whitest on inner wing. Adult male is black and white with yellow eye.
Feb. 2012, Michelle and Peter Wong.
Adult female is dark brown above with paler dull brown flanks and chest, white undertail coverts and deep yellow eye. Can show white around base of bill similar to Greater Scaup, but usually much smaller in extent and has broad black bill tip. Juvenile similar to female but paler with buff area at base of bill.
VOCALISATIONS
Generally silent away from the breeding grounds. Occasionally in flight utters a short slightly inflected rolling ‘kerr’.
DISTRIBUTION & HABITAT PREFERENCE
The majority of records have occurred in the Deep Bay area as far as Nim Wan, with the largest daytime counts made at Tsim Bei Tsui, which gives a vantage point for the coastal waters of Inner Deep Bay and nearby areas. In addition, coordinated evening roost counts of duck at Mai Po NR from 2007 to 2014 also recorded very high numbers of birds roosting on the reserve, including one of the highest counts this century: 4,285 on 15 January 2007.
There have been rather few records away from the Deep Bay area. Three males at Plover Cove Reservoir on 6 February 1972 is the only record from a reservoir. Most of the non-Deep Bay area records are from Starling Inlet and Nam Chung, where up to two have occasionally been recorded since 1993 from 6 November to 29 January, and on 6 March. In addition, one was at Shuen Wan during 1-29 December 2015.
OCCURRENCE
As Figure 1 indicates, until the mid-1990s the wintering flock of Tufted Duck was relatively small, with the highest count being 132. The winter of 1995-96, however, saw the beginning of an increase to 1,667 in winter 2004/05, followed by a steeper increase to 4,285 in winter 2006/07 and 5,543, the highest count on record in HK, in winter 2012-13. Numbers in the whole Deep Bay area (including Fu Tian) were also very high from winter 2008/09, reaching a peak of 11,613 in winter 2016/17. Recent winter periods have seen substantially lower numbers present.
The earliest double-figure count in autumn has occurred on 17 October and the earliest three-figure counts occur in the second week of November. Figure 2 illustrates the pattern of occurrence from November to March as recorded by monthly waterbird counts since 1998. After mid-April generally only single-figure counts have been made, and one or two birds occasionally remain through the summer.
The only report from the years before 1958 was by Herklots (1953), who reported two males and five females in Deep Bay on 14 April 1941. The lack of reports suggests the species was much rarer than it is now.
BEHAVIOUR, FORAGING AND DIET
Molluscs are stated to be a major food item by Carboneras and Kirwan (2020), and the regular presence of diving birds in the intertidal waters of Deep Bay suggests that is the case here also. Generally, a gregarious species that forages and roosts in large flocks.
RANGE & SYSTEMATICS
Monotypic. Breeds across northern Palearctic from Iceland and western Europe to Kamchatka between 45oN and the Arctic Circle, and winters to the south as far as central Africa, the Middle East, the Indian subcontinent, northern Indochina, south China, South Korea and Japan (Carboneras and Kirwan 2020). In China breeds in north and northwest Xinjiang and the northeast, and winters from the Yangtze south to the coast, including Hainan and Taiwan (Liu and Chen 2020).
CONSERVATION STATUS
IUCN: Least Concern. Population trend stable.
Figure 1.
Figure 2.
Carboneras, C. and G. M. Kirwan (2020). Tufted Duck (Aythya fuligula), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.baepoc1.01
Herklots, G. A. C. (1953). Hong Kong Birds. South China Morning Post, Hong Kong.
Liu, Y. and Y. H. Chen (eds) (2020). The CNG Field Guide to the Birds of China (in Chinese). Hunan Science and Technology Publication House, Changsha.
